Exclusion seals, which are sometimes referred to as dust seals, are well known in the prior art. Various forms of such seals are shown in U.S. Pat. Nos. 4,491,332; 3,703,296; 3,640,540; and 3,504,917. Exclusion seals are often used in off-road vehicles to reduce the deleterious effects of foreign matter (e.g., grit from mud and dust) on the sealing lips of seals for preventing egress of oil or grease from vehicle components such as transmission and axle housings.